English kings from the tenth century, including William the Conqueror and his immediate successors Henry I, Stephen and Henry II are known to have bound themselves by a threefold promise:

1. to preserve peace and protect the church;
2. to maintain good laws and abolish bad;
3. and to dispense justice to all.

Elizabeth II included this fourth:
4. I will to the upmost of my power maintain the Laws of God and the true profession of the gospel.